We are in for some beautiful days with great snow, but sunshine and powder aren't always the best combination. Be cautious on steep, solar aspects where the power of the sun may trigger avalanches.
Weather Forecast
We are in for a prolonged dry spell due to a high pressure system. Today expect temps ranging from -18 t0 -8 with light to moderate N'ly winds at ridgetop. Most of Rogers Pass should be above the valley cloud and get plenty of sun. Temps will gradually warm over the next few days, with an inversion and above freezing temps expected by Friday.
Snowpack Summary
Cold temps are slowing the settlement of last weeks snow and causing surface facetting which is helping to keep the surface snow soft. 30-40cm of lower density snow sits on a well settled mid pack. Moderate S'ly winds over the weekend shifted to N'ly yesterday, windloading the immediate lee of alpine features and creating areas of thin wind-slab.
Avalanche Summary
Yesterday there were numerous loose, solar triggered avalanches. They were up to size 1.5 and were occurring from steep, rocky terrain exposed to the sun. On Monday, a skier accidentally triggered a size 1.5 avalanche on a W aspect at ~2200m while descending "NRC" on the Macdonald West Shoulder. There have also been glide crack releases observed.
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.